For P.S. -- Seiko 4006-6031 BellMatic Service - YouTube
Vintage Seiko Bell-matic 4006-6031 Gold Plated Auto Men's - Etsy
Seiko Bell Matic 17J 4006-6031 Alarm Function Analog Vintage Made in Japan | eBay
Beautiful Seiko Automatic Bell Matic 4006 6031 - Etsy
Seiko Bellmatic 4006-6031 May 1974 STC Stelux President Bracelet Was NOS V/G/C | WatchCharts
Sold at Auction: A VINTAGE SEIKO BELLMATIC WRISTWATCH; ref. 4006-6031, in stainless steel with dark blue dial, center seconds, day date, alarm functi...